Environmental sampling and data collection involves the collection of: discrete air, soil, surface water, and/or groundwater media samples. Samples are collected for analysis of physical and chemical properties that provide an indication on the environmental condition of the sampled media. Historically field sample analysis results were recorded by hand in a field notebook. The location of the collected sample was noted in the field book or marked on a printed map or aerial photograph.
A specific example involves landfills. In landfills, trash is compacted and then buried. In these anaerobic conditions, bacteria breaks down organic substances in the trash, thereby producing methane gas. The methane produced varies across and within landfills, depending on, for example, the type of trash, the moisture content, and the weather. While a fraction of this gas may be captured, e.g., by a gas recovery system, the rest is emitted into the atmosphere. Landfills are a primary source of emissions of methane to the atmosphere.
State and local governments (e.g., through the Clean Air Act) have set limits on the amount of methane that may be emitted by landfills. If the emissions exceed this amount, the landfill must take action (e.g., by collecting and combusting or utilizing methane) to reduce the emissions. Thus, there is a need for measuring methane gas emissions to assess possible environmental impact and predict or assess whether a landfill is in compliance with environmental regulations.